CODEWITHSUNDEEP
javaandroidfirebasefirebase-realtime-database
1nullpointer
1nullpointer

Reputation: 1262

Firebase - Best way to reorder entries in realtime Database

Am trying to build a Queue management app. And I use Firebase push() to add new entries into Firebase real-time database. And the order of insertion is my default set.

For a particular scenario - I want to push some elements down by 2 or 3 steps . Whats the best way to do it ? Do I need to use firebase functions? Or Will I need a separate server to handle this logic ?

Example : Say , I have a set of 10 push requests from different client apps who want to get into the queue . When the client doesn't arrive , i want to push them 5-7 places down in the queue.

Is there a good approach to handle these scenarios without a server

I was trying to put the logic on the client side but I guess it wouldn't help much if the client goes offline when using the phone.

Also, I don't have a queue number set as a child element , since the insertion order is being taken care by firebase . A queue# I guess would create conflicting entries if 2 + clients are trying to enter the queue simultaneously .Not sure if this is the right approach.

Upvotes: 1

Views: 2108

Answers (1)

Alex Mamo
Alex Mamo

Reputation: 138869

Unfortunately, you cannot change the order of the nodes in the Firebase Console. All the nodes are by default ordered by key. If you need to order your database elements by a specific criteria, just add another property in your item object that will help you build a query that retrieves the items in the order you want. Let's say you want to order your items by timestamp and you have a database structure that looks like this:

Firebase-root
   |
   --- users
        |
        --- uid
             |
             --- name: "John"
             |
             --- age: 22
             |
             --- creationDate: 1534424049

To order your users by the date of creation, you should use a query that looks like this:

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
Query query = rootRef.child("users").orderByChild("creationDate");

Upvotes: 1

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